首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   62篇
  免费   0篇
林业   1篇
  5篇
水产渔业   4篇
畜牧兽医   48篇
园艺   1篇
植物保护   3篇
  2022年   3篇
  2021年   6篇
  2016年   2篇
  2015年   1篇
  2014年   4篇
  2013年   2篇
  2012年   8篇
  2011年   5篇
  2010年   5篇
  2009年   7篇
  2008年   6篇
  2007年   1篇
  2006年   1篇
  2005年   3篇
  2004年   1篇
  2003年   3篇
  2002年   3篇
  2001年   1篇
排序方式: 共有62条查询结果,搜索用时 15 毫秒
51.
At necropsy, a white nodule (about 5 × 3 mm in size) was observed in the right submandibular gland of a 10-week-old female GALAS rat. Histopathologically, oval to spindle-shaped and pale basophilic tumor cells proliferated closely, and formed variably sized foci. The nodule partially spread into or invaded the surrounding normal tissue, and necrotic foci were recognized in the tumor. Immunohistochemically, the nuclei of the tumor cells showed a diffusely positive reaction for p63, and the cytoplasm showed a diffusely positive reaction for cytokeratin and negative reaction for αSMA, vimentin, desmin and S-100. Many tumor cells were positive for PCNA. Ultrastructurally, the tumor cells contained many tonofilaments in the cytoplasm and a few desmosomes at the intercellular portion. Based on these findings, the tumor was diagnosed as a basal cell carcinoma originating from the duct in the rat submandibular gland.  相似文献   
52.
Skin lesions possibly caused by Papillomavirus infections in two four-toed hedgehogs are described. In case 1, there was a papillary mass on the right hind limb. Histologically, the mass was consistent with a viral papilloma. In the other case, multifocal papillary masses with erosions and ulcers were found throughout the body, mainly on the extremities. Histology showed continuative lesions composed of acanthosis, Bowenoid in situ carcinoma, and squamous cell carcinoma, with abrupt transitions between the lesions. In both cases, keratinocytes in the granular layer infrequently had features of koilocytes and intranuclear inclusion bodies, and immunohistochemical staining was positive for anti-human papillomavirus antibody. To the best of the authors’ knowledge, this is the first pathological documentation of possibly papillomavirus-associated skin lesions in four-toed hedgehogs.  相似文献   
53.
In mammal circulation, various ferritin-binding proteins (FBPs) are thought to be involved in the clearance of circulating ferritin after complex formation with it. However, horse FBPs are known to cause inhibitory effects on ferritin immunoassay due to the concealment of the ferritin molecule to anti-ferritin antibodies used in the ferritin immunoassay. These inhibitory effects are eliminated by heat treatment of horse serum at 75°C for 15 min. The inhibitory effects on ferritin immunoassay in the sera of ten foal sera (5 females and 5 males) from 1 to 18 months were detected during all periods, and ferritin concentrations of the foal sera increased 20–100% as compared with those of untreated sera by same heat treatment. Ferritin concentrations of heat-treated foal sera increased after birth, reaching to ferritin levels of adult horse at 9 months of age. Thereafter, although serum ferritin concentrations fell down at 12 months of age, these concentrations increased to adult levels at 15 months of age again. The ratio of ferritin concentration of heat-treated serum to that of the untreated serum was regarded as an apparent ferritin-binding activity. Ferritin-binding activities in the sera of foals showed peak at 2 and 4 months of age in females and males, respectively. These results suggested that horse FBPs were heat unstable, and FBPs may play an important role in iron metabolism at early developmental stage.  相似文献   
54.
Recent progress in studies concerning behavior of, and management for, grazing cattle are reviewed. Since 1950, much study has been conducted on ‘How’, ‘When’, ‘Where’ and ‘How long’ regarding grazing. After the 1980s, grazing ecology introduced the concept of hierarchy at different spatial and temporal scales, and since then grazing behavior has been investigated on the foraging hierarchy of large grazing herbivores: bite, feeding station (FS), patch, feeding site, camp and home range. From the sequence of activities, FS is grouped within a feeding patch, and movement of grazing cattle has been studied between FSs, feeding patches, feeding sites and between camps. Grazing behavior and production relates closley with defoliation, and grazing management should control both grazing behavior and vegetation according to three rules: planning, operational and adaptation rules. Planning rules relate the stocking rate of cattle; operational rules relate to defoliation; and adaptation rules vary with regional situations. Recent studies on grazing have been carried out in the fields of animal diversity and welfare. Future studies in this field should be conducted on the ecology, neurophysiology and psychology of grazing. Nonlinear analysis will also be significant in this field. Grazing cattle production should also utilize supplementation by roughage and/or grains.  相似文献   
55.
We studied in vivo fiber digestibility and fermentation parameters such as volatile fatty acid concentration and in vitro degradation in each segment of hindgut of horses fed timothy hay or silage made from the same sward. Six Thoroughbred horses were fed timothy hay or silage in equal amounts (1.6% of bodyweight per day, bodyweight mean 572 kg) every 3 h per day, then slaughtered. There were no differences between hay and silage in the concentration of the total volatile fatty acids, the apparent digestibility of dry matter, organic matter, and fiber, and in vitro neutral detergent fiber (NDF) disappearance rate in each segment. The total volatile fatty acid concentration and the apparent digestibility of dry and organic matter and fiber differed ( P  < 0.01) depending on the digestive segments. Both for hay and silage, the concentration of total volatile fatty acids in the digesta liquid phase largely increased ( P  < 0.01) from the cecum to the right ventral colon, and kept a constant value from the right ventral colon to the right dorsal colon, and then decreased from the right dorsal colon to the small colon. For dry and organic matter and fiber components, the apparent digestibility changed in the same manner from former to hinder segments of the hindgut. Regardless of diet, dry and organic matter and fiber components showed lower values in the cecum and the right ventral colon and increased ( P  < 0.01) largely from the right ventral colon to the left dorsal colon, then kept constant values in segments to the rear of left dorsal colon. There were no differences in in vitro NDF disappearance among cecum, ventral colon and dorsal colon.  相似文献   
56.
为确定细胞色素P450酶系在白腐菌Phlebia lindtneri降解有机氯类农药氯丹中的作用,在液体培养条件下,以胡椒基丁醚和1-氨基苯并三唑作为细胞色素P450的抑制剂,分析了不同浓度抑制剂对氯丹的降解、代谢产物的生成以及中间代谢物降解的影响。结果表明:与对照相比,高浓度(1.0 mmol/L)胡椒基丁醚或1-氨基苯并三唑处理15 d后氯丹的降解率均下降了约60%,且其代谢产物中除七氯和二氯代六氯的检出量显著增加外,其余环氧化及羟基化代谢产物均未检出;此外,添加高浓度的抑制剂可导致白腐菌降解中间代谢产物七氯及二氯代六氯的降解率下降90%以上,氧化氯丹的降解率下降70%以上,但不影响环氧七氯的降解。表明细胞色素P450可能是氯丹降解的主要酶系,其参与催化了氯丹的初始羟基化和水解、七氯和二氯代六氯的环氧化及氧化氯丹的水解等多个反应过程。  相似文献   
57.
We previously described that supplementary garlic, onion and purple sweet potato (PSP) enhance humoral immune response in White Leghorn chickens. In the present in vitro study, we investigated the effects of garlic (GE), onion (OE) and PSP (PSPE) extracts on proliferation, interleukin (IL)‐2 and interferon (INF)‐γ gene expression of stimulated lymphocytes. The effects on microbicidal activity, reactive oxygen species (ROS) and nitric oxide (NO) productions of stimulated peritoneal macrophages were studied as well. The results showed that GE augmented Concanavalin A (ConA)‐induced splenocytes (4, 8 and 16 µg/mL) and thymocytes (2, 4 and 8 µg/mL) proliferations, and gene expression of IL‐2 (8 and 16 µg/mL) and INF‐γ (16 µg/mL). None of the examined extracts had mitogenic effect nor stimulated bursacytes response to phorbol 12‐myristate 13‐acetate (PMA). Macrophages exhibited superior microbicidal activity and ROS production with GE at 4 and 8 µg/mL and with OE at 25.6 µg/mL. None of the extracts showed stimulatory effects on NO production. The extracts showed concentration‐dependent inhibitory effects on all measured parameters at higher concentrations. Taken together, it is likely that garlic has direct stimulatory effects on immune cell functions, whereas the in vitro inhibitory effects of onion and PSP were likely attributed to high flavonoid contents.  相似文献   
58.
In vitro gas production (GP) method was used to investigate associative effects on ruminal digestion when grains (corn or barley) were supplemented to spring pasture and autumn pasture. Pasture (75%) was incubated with 25% corn or barley and gas production was monitored up to 96 h. After incubation, the residues were used to determine dry matter and organic matter digestibility (DMD and OMD). Gas production parameters were analyzed by applying a single exponential equation. Organic matter effective degradability (OMED) was determined from GP parameters and OMD. The positive associative effects on the rate of GP, DMD, OMD and OMED were observed when spring pasture was incubated with corn. However, similar effects were not observed in a barley mixture. However, for autumn pasture, both corn and barley mixtures showed positive associative effects on rate of GP, OMD and OMED. The results of this study indicated that supplementation of corn would be better than barley for spring pasture with high water‐soluble carbohydrate contents, whereas both grain supplementations were effective to obtain positive associative effects on the rate of GP and OMED for autumn pasture with high cell wall content.  相似文献   
59.
The Nagoya breed is a native chicken of Aichi Prefecture, Japan, a dual‐purpose breed for eggs and meat. A method for distinguishing the Nagoya breed from Aichi Prefecture from other chickens using five microsatellite markers (ABR0015, ABR0257, ABR0417, ABR0495 and ADL0262) has already been utilized in order to check the authenticity of Nagoya breed‐labeled chicken on the market. The present study was conducted to investigate nucleotide sequences and sizes of PCR fragments containing the five microsatellite regions for the Nagoya breed and to confirm that the genomic identification could continue to be applied in the future. The DNA sequencing of fragments containing the five markers showed that ABR0015, ABR0417 and ABR0495 had a single haplotype, ABR0257 had three haplotypes, and ADL0262 had two haplotypes, although all the markers exhibited one fixed fragment size each upon sequencing of the fragments and fragment analysis. The results of the fragment analysis of each marker using DNA samples of 28 Nagoya breed males (G0 generation) reared in 2000–2001 and 20 of their offspring males (G8) reared in 2008–2009 showed one fixed fragment size in both populations. Therefore, we confirmed that the five microsatellite markers are useful tools for accurately distinguishing the Nagoya breed from other chickens.  相似文献   
60.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号